Year Percent change 1980 1.423 1981 8.282 1982 13.485 1983 6.664 1984 4.708 1985 -0.759 1986 2.916 1987 6.051 1988 5.808 1989 12.144 1990 4.331 1991 2.668 1992 14.722 1993 11.25 1994 12.563 1995 13.133 1996 6.359 1997 11.495 1998 3.889 1999 4.87 2000 16.038 2001 2.28 2002 17.205 2003 12.382 2004 15.147 2005 11.52 2006 10.262 2007 17.872 2008 1.587 2009 -0.536 2010 24.908 2011 12.327 2012 0.935 2013 7.665 2014 4.94 2015 -6.987 2016 7.92 2017 5.273 2018 10 2019 8 2020 8 2021 8 2022 8.5 2023 8.5 2024 8.5